Massby



3 5 place.

UNITED STATES PATENT OFFICE.

HIMsELF, MADIsoN` EDWAnDs, on GHoLsoN, Mississirri, AND

THOMAS JEFFERSON EDMONSON, OF BIRMINGHAM, ALABAMA. i

POWER-JACK.

SPCIFICA TION forming part of Letters Patent No. 315,309, dated April 7, 1885.

Application filed August 29, 1884. (No model.)

To all whom it may ooncern:

Be it known that I, JOHN WAsHINGToN MAssEY, of Shuqualak, in the county of Noxubee and State of Mississippi, have in'vented a 5 new and Improved Power-Jack, of which the designed as an improvement upon the jack for which Letters Patent No. 291,370 were granted to me, conjointly with Madison Edwards as assignee, January 1, 1884.; and the invention consists of certain constructions,ar-

' rangements, and combinations of parts, all as hereinafter described. i

Reference is to be had to the accompanying drawings, forming part of this specification, in which similar letters of reference indicate :o corresponding parts in all the figures,

Figure 1 represents a side View of a power- `jack embodying my invention. .Fig. 2 is a plan of the same; and Fig. 3, a transverse section on the line x x in Fig. 1, omitting certain 2 5 swinging hooks attached to the rack-bar.

A is a longitudinally slotted main post mounted upon and which may be cast in the same piece with a base-plate, A'.

B is a bracket or head-piece fitted by a lower socket on or over tenon-like projections on top of the two sides of the slotted or double post A, and secured thereon by one or more bolts, b, which provides for removal of the bracket in order to fit the rack-bar G to its This rackbar is guided by and fitted to slide through the bracket B on the rear side of the post A, and is provided at its lower end on its face or rack side with a bar or plate, D, which passes through the slot o of the post,

40 and carries on its front end certain holdingeccentrics E E, to prevent back slip of the rack. By this construction the slotted main post'A also serves,conjointly with the bracket B, to guide and steady the rack -bar. The rear projection, d, at the lower end of the rack-bar adapts the jack to be used for lifting Vertical] y objects situated near the ground, and also adapts it to various uses in a horizontal position. The hooks e,which are pivoted to the virtually formsa tail-piece from said pinion,

8 being the shaft or fulcrum arranged to fit within inclined slots or slotted cheeks of the bracket B, so that when said fulcrum s stands at the inner ends of said slots to engage the pinion with the sliding rack-bar the moving of the lever downward or backward will cause the'bar O to bc raised or forced outward to give the necessary lift or thrust. The other or outer portion, G', of the Operating-lever is united by one or more clips, g, with the tailpiece or portion G, and may readily be fitted thereto or unshipped therefrom, or another outer lever portion of anydesired length be substituted for it, as circumstanoes may require. The outer ends of the slots f are left open,so that the entire lever G G' and toothed head G2 may be removed to faoilitate transportation or packing away. The toothed head GZ and the rack-bar G are both similarly strengthened by shrouds arranged on opposite sides of the teeth for half their depth, (more or less.) The eccentrics E E,which are fitted to turn by a shaft, k, connecting them,

within a bearing in the forward portion of vented and the jack be firmly held or lockedto its thrust more securely than canbe attained by ratchet-pawls, and the looking device Will be in a measure selfoperating, any increased backward thrust only strengtheningthe lock. By releasing pressure from the treadle or presser F, or slightly lifting on it before starting the rack-bar outward or moving it inward,

said eceentrcs will in nowise interfere with the sliding inovernent of the raek-bar- The general operation of the jack, so far at least as the Working of the rack-bar and toothed-headed lever is eonoerned, is similar to that deseribed in my former Letters Patent, hereinbefore referred to.

Having thus described my invention,I claim as new and desire to secure by Letters Patent- 1. The combination of the slotted post A, the slidng rack bar O, the bar or plate D, attaehed to the rack-bar and arranged to pass through the slotin said post, one or more turning eecentries, E, carried by the plate or bar 011 the opposite side of the post to that of the rack-bar, and the treadle-lever or presser F, applied to control the Vrnotion or adjustment of the eccentrics, substantially as speeified.

2. In a raek-and-pinion power -jack, the

co1nbination,with the sliding rack-bar O, and 20 the braeket B, having inelined slots, of the eomponnd lever G G', having its Sections united by one or more clips, g, the toothed head or pinion G2, fast on the inner end of the one lever portion G, and the fulcrnrn or shaft 25 

